Blade lifter especially for strongly abrasive substances

ABSTRACT

A blade lifter adapted for installation within a rotary kiln drum used in the treatment of abrasive substances comprises a mounting portion and an inwardly projecting blade portion formed integrally with one another, the surfaces of the blade portion being profiled by means of ribs projecting from the surfaces of the blade portion.

United States Patent [1 1 Vering [451 Apr. 30, 1974 BLADE LIFI'ER ESPECIALLY FOR STRONGLY ABRASIVE SUBSTANCES [75] Inventor:

[73] Assignee: Polysius AG, Neubeckum, Germany [22] Filed: Feb. 2, 1973 [21] Appl. No.: 329,068

Anton Vering, Vorhelm, Germany [30] Foreign Application Priority Data Apr 13, 1972 Germany 7213794 [52] U.S. Cl 432/103, 432/118, 34/166, .'34/108,110/14 [51] Int. Cl. F27b 7/14 [58] Field of Search 432/103, 108, 118, 106; 34/165, 166, 173, 108, 109, 137, 124, 125; 110/14 [56] References Cited UNlTED STATES PATENTS 2,104,040 H1938 Hurt 432/106 3,025,611 3/1962 Freeman 34/137 3,407,511 10/1968 Camm 34/137 2,190,271 2/1940 Powell 432/108 Primary Examiner-John J Camby Assistant Examinerl-lenry C. Yuen Attorney, Agent, or Firm-Lea'rman & McCulloch [57] ABSTRACT A blade lifter adapted for installation within a rotary kiln drum used in the treatment of abrasive substances comprises a mounting portion and an inwardly projecting blade'portion formed integrally with one another, the surfaces of the blade portion being profiled by means of'ribs projecting from the surfaces of the blade portion.

10 Claims, 6 Drawing Figures BLADE LIFTER ESPECIALLY FOR STRONGLY ABRASIVE SUBSTANCES The invention concerns a blade lifter especially for strongly abrasive substances and intended for installation inside a rotary kiln. I

Lifting members are generally installed on the inner peripheral surface of drums used in thermal treatment of strongly abrasive substances (e.g., as used for cement clinkers) and serve to lift the material being treated within the drum.

It has been repeatedly observed that prior art blade lifters having a smooth surface'lack the desired rigidity. Experiments designed to achieve greater rigidity by increasing blade thickness nevertheless resulted in a rather awkward model which, in addition, is rather expensive because of the increased amount of construction material required. Furthermore, prior art blade lifters have a comparatively short service life, thus requiring exchange too frequently, particularly when used for strongly abrasive substances. This leads to needless frequency of shutdowns as well as considerable additional expenditures for construction material and installation costs.

Therefore, an object of the present invention is to provide a blade lifter of the type mentioned above, which is characterized by a comparatively simple construction while demonstrating great rigigidty and strength.

In accordance withe the invention, at least part of the lifting member is provided with a profile manufactured as part of the entire lifter blade in one piece with the latter.

A blade lifter with a profiled surface according to the invention is considerably more rigid than prior art versions. This is achieved while keeping the blade comparatively thin and using a comparatively small amount of construction material. A profiled contour furthermore increases the surface area of the blade lifter, which in turn increases the amount 'of heat emitted by the blade member when installed in drums designed for thermal treatment of materials.

One of the preferred embodiments of the invention calls for a profile comprising pouch-like recesses. Part of the substance being treated, particularly if it is a finegrained material, will deposit in these cavities, forming a natural protection with respect to wear and abrasion and thus prolonging the service life of the lifting mem-' ber.

If the blade lifter of the invention is made of cast metal, profiling increases the surface hardness of the crust, thus improving the strength of the lifting member still more.

Embodiments of the invention are illustrated in more detail in the following description and drawings:

FIG. 1 is a sectional view (taken along the line II of FIG. 2) of the blade lifter according to the invention;

FIG. 2 is a partial plan view of the blade lifter shown in FIG. 1;

FIG. 3 is a fragmentary plan view of the surface profile of a bladelifter (in the direction of arrows X shown in FIG. 1);

FIG. 4 is an enlarged fragmentary section taken on line lV-IV of FIG. 3; and

FIGS. 5 and 6 illustrate two additional fragmentary plan views of other profile shapes possible for the Surface of the blade lifter (in the direction of arrows X shown in FIG. 1).

The blade lifter according to the invention as illustrated in FIGS. 1 and 2, consists for the most part of blade portion 2 in addition to a slightly curved portion 3 adapted to the curvature of the kiln shell (not illustrated), into which blade lifter 1 is to be installed. It is practical to have blade lifter 1 consisting of blade portion 2 and the curved part 3 manufactured in one piece from cast metal (e.g., cast steel).

Blade, portion 2 comprises curved part 4, which in this embodiment has a quadrantal cross section, as well as two faces 5 and 5a. The profile found on inside surface 6 and on outside surface 7 of curved part 4 of the blade lifter, is cast in one piece with the remaining part of the lifting member.

In general, it should suffice to provide only surfaces 6 and 7 with a profile, since it is the curved part 4 of blade portion 2 which is subjected to the most wear, particularly with respect to the material undergoing treatment inside the drum. It is, of course, possible to provide a profile on all other portions of blade lifter 1 that come in contact with the substance being treated.

Furthermore, scoop rim 8 of blade portion 2 is equipped with a reinforced edge to guard especially against wear and abrasion.

As shown in FIGS. 3 and 4, the profile on sides 6 and 7 of the blade surface can be provided by intersecting ribs.

The intersecting ribs of the profile pattern shown in the embodiment illustrated in FIG. 3 are positioned with respect to each other such that they form pouchlike recesses 10, having a surface area in the shape of a rhombus or rhomboid (see also the corresponding partial cross-section of FIG. 4). If desired, and useful,

ribs 9 may also have a rectangular cross-section (as shown .in FIG. 4) or a cross-section which is tapered toward the outside.

Of course, it is possible for the recesses to have different surface areas, e.g., that of a square or a rectangle.

Finally, as illustrated in FIGS. 5 and 6, it is possible to equip the profile manufactured in one piece as part of blade portion 2 with rib-like projections, each of which may form a complete circle 11 (see FIG. 5), or a complete rectangle 12 (see FIG. 6), or something similar. Such ribbed projections 11 or 12 would also form pouch-like recesses, open toward the outside. Depending upon the purpose for which blade lifter l is to be used, ribbed projections 11 or 12 might be spaced more or less closely together, whereby adjacent projections might be arranged in a straight line (as illustrated in FIG. 6) or they might be staggered as shown in FIG. 5.

In each of the embodiments just described, the lifting member of the invention has a comparatively thin blade portion 2, yet the entire member is characterized by an extremely great rigidity, as well as by a considerably improved surface hardness of the crust compared with that of prior art versions. As a result of the recesses formed by the profile pattern, that part of the surface of blade lifter l which is subjected to the greatest amount of abrasion (as noted above), acquires a very strong resistance to wear and abrasion, thereby considerably increasing the service life of the inventive lifting member.

I claim:

1. A blade lifter adapted for installation within an abrasive substance treatment drum, said blade lifter comprising a mounting portion adapted for mounting on said drum, and a blade portion extending from said mounting portion in a direction to project inwardly of said drum, said blade portion having a profiled surface formed by a plurality of upstanding spaced apart ribs constituting an integral part of said blade portion, the spaces between adjacent ribs forming recesses.

2. A blade lifter according to claim 1 wherein both surfaces of said blade portion are profiled.

3. A blade lifter according to claim 1 wherein said recesses are pouch-like in configuration.

4. A blade lifter according to claim 1 wherein said ribs intersect.

5. A blade lifter according to claim 4 wherein said ribs have a predominantly rectangular cross-section.

6. A blade lifter according to claim 4 wherein said ribs taper outwardly from said blade portion.

7. A blade lifter according to claim 1 wherein said ribs comprise complete circles.

8. A blade lifter according to claim 1 wherein said ribs comprise complete rectangles formed by ribs upstanding from said blade portion.

9. A blade lifter according to claim 1 wherein said ribs comprise complete rhomboids formed by ribs upstanding from said blade portion.

10. A blade lifter according to claim 1 wherein said blade portion and said mounting portion are formed of cast metal. 

1. A blade lifter adapted for installation within an abrasive substance treatment drum, said blade lifter comprising a mounting portion adapted for mounting on said drum, and a blade portion extending from said mounting portion in a direction to project inwardly of said drum, said blade portion having a profiled surface formed by a plurality of upstanding spaced apart ribs constituting an integral part of said blade portion, the spaces between adjacent ribs forming recesses.
 2. A blade lifter according to claim 1 wherein both surfaces of said blade portion are profiled.
 3. A blade lifter according to claim 1 wherein said recesses are pouch-like in configuration.
 4. A blade lifter according to claim 1 wherein said ribs intersect.
 5. A blade lifter according to claim 4 wherein said ribs have a predominantly rectangular cross-section.
 6. A blade lifter according to claim 4 wherein said ribs taper outwardly from said blade portion.
 7. A blade lifter according to claim 1 wherein said ribs comprise complete circles.
 8. A blade lifter according to claim 1 wherein said ribs comprise complete rectangles formed by ribs upstanding from said blade portion.
 9. A blade lifter according to claim 1 wherein said ribs comprise complete rhomboids formed by ribs upstanding from said blade portion.
 10. A blade lifter according to claim 1 wherein said blade portion and said mounting portion are formed of cast metal. 